The present invention relates to endless belts, and particularly to such belts that are suitable for conveying articles, and more particularly to a bowling pin conveyer apparatus, and specifically to such apparatus incorporating endless belts for conveying bowling pins from a collection area to a pinsetter apparatus.
A bowling pin conveyer apparatus or mechanism, hereafter, pin conveying apparatus, typically embodies one or more elongate chutes, each having a forward end and a rearward end. The chute comprises a bottom surface extending from the forward end to the rearward end, and two juxtaposed, oppositely facing walls, similarly extending from the forward end to the rearward end of the chute, and intersecting the bottom surface to define chute corners. The chute is commonly arranged to define a conveying area that is inclined in relation to the ground.
Two endless belts traverse the length of the chute and are typically situated one each at or near the respective corners of the chute. The belts are trained about at least a driver sprocket or pulley located outside the chute and near its rearward end, and a driven sprocket or pulley, similarly located outside the chute but near its forward end. The chute is typically formed such that its effective width accommodates the breadth of a standard-sized bowling pin lying on its side, with its base directed to the rearward end of the chute.
In operation, a feeding apparatus delivers one or more bowling pins, hereafter, xe2x80x9cpinsxe2x80x9d, from a collection area to the forward end of the chute, which generally defines a mouth or pin-receiving portion. As the belts are driven about the pulleys, a lateral portion of the pin first contacts at least a portion of the pin-engaging or -contacting surface of one or both belts. The pin is then urged through surface contact with the moving belt pin-contact surfaces to the proper position within the chute, and is thence conveyed through the chute through surface contact with respective pin-contact portions of the opposing belt pair, and ultimately out a rearward end of the chute to a pin setter apparatus.
Traditionally, endless belts utilized in such applications have been formed such that at least their pin-contacting surface exhibits low hardness characteristics, to provide the frictional characteristics necessary to establish contact with and convey bowling pins from the collection area to the pinsetter apparatus. The low hardness material generally utilized for such applications has been a conventional, general purpose polychloroprene composition. Such low hardness compositions tended to deform to the shape of the pin on contact therewith, allowing for an increase in surface area contact with the pin.
The frictional characteristics of bowling pins however have changed over time through the application of low-coefficient of friction coatings now widely employed to prevent or minimize deterioration of the pin surface. Low coefficient of friction oils increasingly used on bowling lanes, which are frequently transferred to the bowling pin surface in use, further contribute to the decreasing effective coefficient of friction at the pin surface. Conventional low hardness polychloroprene compositions utilized in belt sidewalls proved largely ineffective in conveying these low-coefficient of friction-coated pins.
Attempts at modifying conventional polychloroprene compositions for use in such belts to adjust their frictional characteristics in order to effectively convey the pins have included incorporating additional plasticizers in the elastomer compositions; reducing reinforcing and semi-reinforcing fillers (such as carbon black, silica, clays, etc.); and conversely increasing the polymer content of the compositions.
While each of these methods has been at least somewhat effective in reducing the initial hardness of the resultant compositions, changes in the belt pin-contacting surface nonetheless occur over time; it is believed that the polychloroprene compositions gradually harden due to their tendency toward crystallization over time, to a point where they can no longer effectively convey the pins. This polymer hardening effect is believed to have a greater impact on the polychloroprene elastomer""s pin-conveying effectiveness, than the polymers"" coefficient of friction.
According to the present invention, an endless belt is provided comprising a first layer extending longitudinally of the belt and comprising a first flexible material, and a second layer generally parallel with the first layer and comprising a second flexible layer composition, and a load carrying section embedded in the belt, wherein at least one of the first flexible material and the second flexible material comprises an elastomer blend composition comprising at least a polychloroprene elastomer and an ethylene alpha olefin elastomer.
In another embodiment, such endless belt suitable for use within a pin conveying apparatus is provided.
In a further embodiment an endless belt is provided for incorporation in a pin conveying apparatus having endless members including two such juxtaposed belts, each of which comprises a pin-contacting portion, a driving surface and a load-carrying member disposed proximate the driving surface and extending along the length of the belt. At least the pin-contacting portion of the belt is formed of an elastomeric composition comprising a blend of polychloroprene elastomer and an ethylene alpha olefin elastomer.
In a preferred embodiment of the present invention, the ethylene alpha olefin elastomer is ethylene propylene diene terpolymer elastomer, and in another embodiment the ethylene alpha olefin elastomer such as the ethylene propylene diene terpolymer is only partially cured.